Cardiac function management systems are used to treat arrhythmias and other abnormal heart conditions. Such systems generally include cardiac leads, which are implanted at a target location suitable for delivering an electrical stimulus therapy to a patient's heart. A cardiac lead typically includes a flexible conductor defining a central channel or lumen, surrounded by an insulating tube or sheath extending from an electrode at the distal end to a connector pin at the proximal end.
Cardiac lead placement may be accomplished by introducing the lead through a major blood vessel and advancing a distal end of the lead to a target location suitable for electrical stimulation of a patient's heart. The target location may be located near or in a patient's heart or at a location adjacent a nerve or nerve bundle. To facilitate cannulation of the vasculature, it is often helpful to first advance a guiding catheter through the desired vascular path. One difficulty with implanting leads in this fashion is that the cardiac lead has a tendency to become dislodged from its desired location during or after lead implantation. For example, when a clinician withdraws the guiding catheter, the lead may dislodge or otherwise reposition. Until tissue in-growth ultimately fixes the lead at the desired site, cardiac leads may also become dislodged by subsequent physiological activity.